CAPE CANAVERAL, Fla. -- With the scheduled launch of the Space Shuttle Endeavour just a little more than four hours away, NASA officials are "more optimistic" about the weather situation.

Low-lying clouds scrubbed the original launch on Sunday morning and are a threat for this morning's launch. However, things are looking more promising.

There are no technical issues to affect the launch and the crew is beginning its final preparations in its headquarters before soon leaving in the traditional silver Airstream van for the ride to launch pad 39B.